Uncovering the metabolic strategies of the dormant microbial majority: Towards integrative approaches

A grand challenge in microbiology is to understand how the dormant majority lives. In natural environments, most microorganisms are not growing and instead exist in a spectrum of dormant states. Despite this, most research on microbial metabolism continues to be growth-centric, and many overlook the fact that dormant cells require energy for maintenance. In this perspective, we discuss our research program to uncover the metabolic strategies that support microbial survival. We present two major principles underlying these studies. The first is the recent realization that microbial survival depends on previously unrecognized metabolic flexibility. The second is that new discoveries in this area depend on more sophisticated integration of approaches at the molecular, cellular, and ecosystem levels. These principles are illustrated with examples from the literature, including our own work demonstrating that bacteria can live on air, and areas for future methodological and theoretical development are highlighted.